Analysis of yarn tension forces in the weft knitting phase of circular knitting machines

Abstract

In the process of loop formation, the weft knitting phase has a dominant place, both from the aspect of forming the loop as well as determination its length and geometric shape. The loop length is the most important technological parameter in the knitted fabrics structure analysis and it is directly a function of sinking depth. The yarn tension in the weft knitting phase is determined by the following parameters: values of yarn tension at the entrance to the knitting system, yarn friction with knitting needles, yarn guiding speed, yarn bending stiffness and yarn angle coverage with knitting needles. Determination the value of yarn tension in the weft knitting phase is extremely important for the reliability of the knitting process. The obtained results show that the maximum values of yarn tension in the loop formation process occur in the weft knitting phase and that they must not be greater than the forces of the elastic limit of the used yarn.